1. Field of the Invention
The invention relates to a tube coupling comprising a first tubular part and a second tubular part, which parts can be coupled to and separated from one another, the first part comprising a locking member which is movable from a first position, in which the locking member locks the second part relative to the first part, to a second position, in which the locking member releases the second part.
The invention further relates to a tubular part suitable for use as a first tubular part in a tube coupling in accordance with the invention.
The invention also relates to a vacuum cleaner comprising a housing, a suction unit accommodated in the housing, and a suction attachment which can be coupled to the housing via a suction tube and a suction hose, the suction tube comprising at least a first tubular part and a second tubular part, which tubular parts can be coupled to and separated from one another.
The invention moreover relates to a suction tube suitable for use in a vacuum cleaner in accordance with the invention.
2. Description of Related Art
A tube coupling of the type defined in the opening paragraph is known from DE-G-92 13 813. The locking member of the first tubular part of the known tube coupling is a lever which is pivotably mounted in a plastics sleeve of the first part by means of two elastically deformable joints, which constitute a pivot of the lever and which are formed by cut-outs in the sleeve. The lever comprises a first arm with a locking projection and a second arm which is bent relative to the first arm and which forms an actuating knob of the tube coupling. The first part and the second part of the known tube coupling are coupled to one another by inserting the second part into the first part, as a result of which the locking projection of the lever engages a recess in the second part under elastic deformation of the pivot of the lever and the second part is locked relative to the first part. The first part and the second part of the known tube coupling are separated from one another by pressing the actuating knob in a direction perpendicular to a longitudinal axis of the first part, as a result of which the lever is pivoted about the pivot and the locking projection is disengaged from the recess of the second part, and by subsequently sliding the second part out of the first part.
A disadvantage of the known tube coupling is that in order to uncouple the two parts a user should exert a force on the actuating knob, which force is necessary to unlock the two parts and is directed perpendicularly to the longitudinal axis of the first part, and at the same time two mutually opposed forces on the two parts, which forces are necessary to disengage the two parts from one another and are directed parallel to the longitudinal axis of the first part.